op chicago



Reiteued Dec. 17, 1929 UNITED STATES PATENT oFFicE a RICHARD EBICSON, OFCHICAGO ILLINOIS ASSIGNOB' '10 UNITED STATES GYPSUI 00., OF CHICAGO,ILLINOIS, A CORPORATION OI ILLINOIS LIGHT-WEIGHT CERAMIC MATERIAL ANDPROCESS or name THE am 1'0 Drawing. Original No. 1,702,078, datedFebruary 12, 1929, Serial 10. 828,259, fled 14, 1027.

Application for reissue filed October 11, 1929. Serialv No. 899,088.

1 This invention. relates to a porousand light weight cellular ceramicproduct, and a method for producing and manufacturing the samecommercially. I p

Q The use of foam or other density reducsubstance in connection withcemetitious materials to form porous cellular compositions when set andhardened to finalstate with water, is becoming established as onecommercial means of producing a light weight material. I am not awarethat anything of this principle has been applied to the production ofceramic materials where an argillaceous, earthy material is given a Iporous structure by admixture with a tenacious foam reducing agent andsubsequently this porous argillace'ous material is heat-- treated torender its cellular structure fixed in a finished ceramic product.

A comparatively light porous material suitable for structural purposesor suitable as a heat insulator can be made from clay or otherargillaceous earthy material, by first forming a plastic mixture of theearthy material with water, then mixing in a previously preparedtenacious foam or other density 1 to uniform admixture, next forming themass ilito a cast or'shaped product of any desired form, then dryingthis cast to preserve its cell structure, and finally baking or burningthis dried cast until a hardened mass results which retains permanentlyfixed the porous desired fineness state through suitable disin-"tegration or grinding means and rendered. lastic with water. However, inmy process reduce to perhaps a more fluid plastic state than is theordinary practice in the production of common ceramic products likebrick w or tile- This is usually necessary-because the addition of foamto provide the porous structure has bulking effect, and additionalfluid- I lty, 1n the plastic earthy material, is needed 1 to take careof this and to fully preserve the 'foam from breaking down somewhat asit does 1f the plastic mixture itself is too stiff.

The material for forming the foam may conproducing tenacious foam from awater solution such as soap bark, licorice, commercial plaster retarder,glue, soap, resin soap, and various admixtures of these, etc. The foamitself maybe made by beating the water solution violently or byintroducing a cursist of any number of materials capable of that it canbe'readily mixed with water. Sufficient water is then mixed with it toform a plastic mass of such consistency or fluidity that foam canreadily be mixed thereto. With certain shales I have used, this is aboutsix tenths of one part of water by weight to one part of ground shale.used is made by dispersing air into a solution composed of threequartersv of one part of powdered soap bark suspended in one hundredparts of water, and this foam if properly prepared is very stable andpreserves its structure for a long time. The

quantity of foam used is about five parts ofv The foam i foam by volumeto one part by volume of the shale and water mixture, and will give aresultant ceramic product having a density of about thirty pounds percubic foot. The mixture of shale, water and foam is then dried and afterdrying it is baked or burned at about the temperature and method used inburning the ordinary brick or tile products made from the same shale,care being takenffnot to fuse or melt the product during the:iburn ingor firing stage. Afterrthe burning, the, .7 hard porous product is readyfor use in a, variety of ways. If the original shape of the cast was abrick, this finished porous brick is then available for an insulatmgbacking- "other densi' reducing or less stability than the soap barkfoam cited, plastic mixture of argillaceous substance,

of invention. Other up brick in-hi htem rature insulation work. Or-theburnegl pro uct can be crushed and sized into an aggre to for use with acementing material to g ve a moulded and cast structure prepared asdesired on the job. .One use of this crushed product is as a lightweight aggregate in the'production of Portland cement concrete.

I have noticed in some cases. where extremel light weight products(25-30 pounds r cu ic foot density) are desired that these 0am claycasts when dried exhibit some cracking and shrinking. This of course, depends somewhat on the nature of the clay or'shale used as a. base, andis what is ordinarily experienced in the generalmanufacture of ceramicproducts. But in my light weightfoam process, the natural tendency ofthe clay or shale in this direction of course, is an ented, becauseafter the foam addition e composite mix is less dense and consequentlysomewhat fragile. Thus, there is greater opportunity for shrinking andcrackmg during drying to manifest itself. If the fimshed ceramicproducts are to be used as crushed egates this. of courseis immaterial,but if the finished porous light wei ht ceramic product is to be usedintact itself or structural purposes and thus mustretain the fonn andsize which it was cast, some additions mu bemade to the. clay or shalejust as in ordinary ceramic practice to offset this shrinkage andcracking. The addition of silica, flint, grog, and other coarser body.

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materials is usefu in this ca acit have also found a mixture of ca cinegypsum or (plaster of Paris setsrapidl with water an thus hardens thecellular c ay mass sufficientl to withstand the shrinking effect inducedy the later drying. The calcined 14- v: I u mixed with "water can beadded to e mixture of argillaceous material and foam with d results.Accelerating the set by the cined gypsum decreases the time requiredbefore the subsequent mixture stiffens. However when gypsum" is used,more care must be taken in burning the dried pdrous product becauseusually the fusing or melting point ofsuch mixture is lowered by theaddition.

Many modifications of this invention will 4; w themselves'and'I do not.wish to be limited in various applications of thisprinciple, for thevarious modifications that suggest themselves do not depart from thespirit types of argillajceous material other than the natural earthmaterials used may suggest themselves su I I as built-up artificialrefractory raw mate-1 rials made plastic b only smalladditions of claysor shales; an many types'of foam or agents with greaterma be used. Alsoother methods of drying an burning may used than merely presame. Forexam la, the casts may tially dried and t en placed in a rotary ilnwhere they can be further dried and burned the burned product resultinparing unit casts drying and burning the in one operation if thematerial is. intended for use primarily as an a gregate.-

Having thus describe my invention, what I claimis:

1. A porous ceramic material comprising the burned product resultin fromheat treating amixture of foam an argillaceous material.

2. A porous light weight ceramic product com rising burned argillaceousmaterial ma e porous byfoam addition while plastic. 3. A 1i ht weightstructural material comprising t e burned product resulting from heattreating argillaceous material in which a tenacious foam is incorporatedprior to dryinlgv and burnin stance, tenacious foam, and substances cracin during dryin 5. A g

prising t e .burned product resulting from heat treating a mixture ofargillaceous material, foam, calcined gypsum, and water. 6. A porousceramic material comprising treating a mixture of one part y volume'of aplastic mixture of argillaceous material and water, with five parts oftenacious foam. 7. A' cellular ceramic product comprising the burnedproduct resultin from heat treating a mixture of one-part y volume of aplastic mix of argillaceous material and water, four parts of tenaciousfoam, and one third art of calcined a 8.* T e process of manu acturing aporous product com rising forming afluid plastic mixture of terial withwater, incorporatm therein a tenacious foam, shaping and dryingthis'admixture and finally heat treating. a dried porous mass tomaintaina substantial hardened cellular product.

9. Theprocess of manufacturing a porous ceramic material comprising theincorporation of tenacious foam into a fluid plastic mixture ofargillaceous substance and water, thefoam volume being in excess of thevolume ofargillaceous water mixture used, caste ing this resultantmixture into desired shape, drying, and finally burning the dried porousmass at a temperature below its fusion point foam and water, calcinedgypsum to prevent shrinkage durin'gsubsequent loss,

porous ligfitrweight material com-' "prlsing the-burned productresulting from eat treating a mixture of argillaceous sub-.

Eht weight ceramic material comfrom heat nely divided ar 'llaoeous ma- Ydrying I this composite mas, and finally heat treating the dried porousmass at a temperature below its fusion point to yield a hard- I enedporous product.

urmng. o -12. A rous light weight material com burn Erising t e productresulting fromeat treating a mixture ofargillaceous substance, a densityreducing substances adapted to prevent excessivev shrink 15 ingandcracking during drying.

13. A light weight ceramic material our. rising the burned productresultingirom t treating a mat ure of argillacecus material, a densityreducing agent and calcined 14. The proces of manufacturing a porousproduct comprising forming a fluid plastic mixture of finely dividedargillaceous matenal' vith water, incoslflporating 1313mm a (lain; ym ug h w y admixture, and finally heat treating the a! v porous mass tomaintain a substantially h ened, cellular "product.

15. The proces of manufacturin aporous l0 ceramic product, comprising adg to a plastic mixture of-argillaceous substance, a

density reducing agent and water and calcined gypsum to preventshrinkage during subsequent moisture 10s, drying this com- 85 hemixture, and finally heat treating the porous mass at a. tem" ture-belowitsfusion point to yielda ardened, porous ERICSON.

